The invention relates to a spray pyrolysis system which comprises a gas-liquid inlet device (1), a micro-fog generation device (2), a tube furnace (3), a powder collection device (4) and a control device (5). The gas-liquid inlet device (1), the micro-fog generation device (2), the tube furnace (3) and the powder collection device (4) are sequentially serially connected, and the control device (5) is connected with the tube furnace (3). The spray pyrolysis system is high in automation degree, convenient to operate and applicable to preparation of various nano-powder.